Act governing the administration of professional engineering consulting firms Article 21

The professional engineering consulting firms shall, within six months from the day after the end of a fiscal year, submit the annual business report as required by the competent authority to the competent authority for reference.The professional engineering consulting firms shall work out the aforementioned business report on a faithful basis and shall archive the report for a minimum of ten years from the date on which the report are submitted.
中文原文 工程技術顧問公司管理條例第21條
工程技術顧問公司應於年度結束之次日起六個月內,檢具主管機關規定之年度業務報告書,送主管機關備查。
前項報告書,工程技術顧問公司應據實填寫,並自提出報告之日起,至少保存十年。

English translation for reference only; the Chinese text prevails. Not legal advice.